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Water and the Science of Pollution
Published in Daniel T. Rogers, Environmental Compliance Handbook, 2023
Another important measure of toxicity is the lowest observed adverse effect level (LOAEL) or threshold effect value. The LOAEL is the lowest tested dose of a chemical or substance causing a harmful or adverse health effect (ATSDR 2021). Factors influencing the LOAEL include: The chemical's solubility in body fluidsThe particle size and state of the chemicalRoute of exposureResidence time of the chemical in the bodyIndividual susceptibility
Land Contamination
Published in Daniel T. Rogers, Environmental Compliance Handbook, 2023
Another important measure of toxicity is the lowest observed adverse effect level (LOAEL) or threshold effect value. The LOAEL is the lowest tested dose of a chemical or substance causing a harmful or adverse health effect (ATSDR 2021a). Factors influencing the LOAEL include: The chemical’s solubility in body fluidsThe particle size and state of the chemicalRoute of exposureResidence time of the chemical in the bodyIndividual susceptibility
Measurement Method for Orthopaedics
Published in P. Arpaia, U. Cesaro, N. Moccaldi, I. Sannino, Non-Invasive Monitoring of Transdermal Drug Delivery, 2022
P. Arpaia, U. Cesaro, N. Moccaldi, I. Sannino
At the present time, for in-vivo measurements and topical drug application, critical issues are linked to drug bioavailability and bioequivalence, which must be assessed typically via costly and time-consuming clinical studies [179]. In fact, in the case of topical medications, the equivalence between drugs is essentially based on the correlation of the active ingredient, by neglecting the importance of the excipients. In addition, there are no acceptable standard methods for the in-vivo assessment of local cutaneous bioavailability in humans after topical drug application[142, 180]. The systemic availability may not represent local cutaneous bioavailability accurately, as for transdermal or oral products, which are designed on the other hand, to deliver drug into the systemic circulation. The bioavailability is typically defined as the rate and amount of drug that reaches the general circulation from an administered dosage form. Thus, bioavailability assessment of a topical drug is crucial for both the transdermal delivery of pharmacological active drugs and a toxicological point of view.
Synthesis of PEGylated cationic curdlan derivatives with enhanced biocompatibility
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Muqier Muqier, Hai Xiao, Xiang Yu, Yifeng Li, Mingming Bao, Qingming Bao, Shuqin Han, Huricha Baigude
In order to further confirm that PEGylation can reduce the toxicity of 6AC-100 and improve the biocompatibility, we first took the whole blood of C57/BL mice 24 h after the administration of 6AC-2S PEG40 by tail intravenous injection and measured the levels of ALT/AST in serum using 6AC-100 as a control (Figure 5(A)). It can be concluded that at the dose of 100 µg/mouse, the levels of ALT or AST of both 6AC-100 and 6AC-2S PEG40 treated group showed no significant difference compared with the NT group, but at the dose of 200 µg/mouse, the levels of ALT or AST of 6AC-100 were elevated, while 6AC-2S PEG40 showed no significant variation, indicating that 6AC-2S PEG40 has low toxicity in vivo. Next, we carried out an acute toxicity experiment to calculate LD50 values of the PEGylated curdlan derivatives. Again, 6AC-100 used as a control. LD50 is a term used in toxicology to measure the lethal dose of a substance. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. This value is then used as an indicator of a substance’s relative toxicity. Thus, a substance with a high LD50 would have a low toxicity, while a substance with a low LD50 would have a high toxicity. The calculated results showed that 6.82 mg/kg doses of 6AC-100 killed half the mice, while 8.97 mg/kg doses of 6AC-2S PEG40 killed half the mice (Table 4, Figure 5(B)), indicating that 6AC-2S PEG40 was much less toxic compared to 6AC-100.
A difunctional Pluronic®127-based in situ formed injectable thermogels as prolonged and controlled curcumin depot, fabrication, in vitro characterization and in vivo safety evaluation
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Samiullah Khan, Naveed Akhtar, Muhammad Usman Minhas, Hassan Shah, Kifayat Ullah Khan, Raghu Raj Singh Thakur
Maximal tolerated dose refers to the dose at which the target object is observed continuously for toxicity, mortality or morbidity. So MTD indicates the highest dose tolerated by animals included for specific duration of the study. Duration of dosing animals greatly affects MTD, because in some cases consecutive higher doses might not be tolerated by animals for longer duration. So animals were administered a range of dosing 100–2000 mg/kg body weight. As no mortality or abnormal signs were found at higher tested dose, so MTD of curcumin loaded in poly(PF127-g-AMPS) gels was found 2000 mg/kg body weight through subcutaneous injection.
The enhanced removal and phytodegradation of sodium dodecyl sulfate (SDS) in wastewater using controllable water hyacinth
Published in International Journal of Phytoremediation, 2019
Ying Gong, Jiping Chen, Rongping Pu
As displayed in Table 6, all the detected degradation intermediates had higher LD50 values than that for SDS. As we know, the value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity and a lower LD50 is indicative of increased toxicity (https://en.wikipedia.org/wiki/Median_lethal_dose). As a result, the degradation products were safer than SDS.